Urethane (METH)acrylate, method for producing urethane (METH)acrylate, active energy ray-curable resin composition and transfer film

Abstract

To provide a urethane (meth)acrylate capable of obtaining a cured product layer which achieves both scratch resistance and extensibility.SOLUTION: There is provided a urethane (meth)acrylate which has a unit derived from a carbonate polyol compound (A) having a terminal hydroxyl group, a number-average molecular weight of 500 or more and 1500 or less and no cyclic skeleton, a unit derived from an alkyl alcohol compound (B) having two or more hydroxyl groups having 10 or less carbon atoms, a unit derived from an alicyclic polyisocyanate compound (C) and a unit derived from a hydroxyl group-containing (meth)acrylate compound, wherein the NCO / O ratio, which is the molar ratio of the isocyanate in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups of the hydroxyl group in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B) is 1.15 or more and the urethane (meth)acrylate has a unit derived from the (D) at the molecular chain terminal.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a urethane (meth)acrylate, a method for producing a urethane (meth)acrylate, an active energy ray-curable resin composition, and a transfer film. [Background technology]

[0002] Curable resin compositions that are cured by irradiation with active energy rays such as ultraviolet rays and electron beams are known. When the curable resin composition is cured, a cured product having good functionality such as scratch resistance and chemical resistance is formed. Therefore, the cured product is used as a surface protection layer that protects the surface of a substrate such as wood, metal, glass, or a resin molded product.

[0003] Compositions containing urethane (meth)acrylates are known as curable resin compositions. For example, Patent Document 1 discloses a resin composition for energy ray-curable coating agents, which contains a carbonate bond-containing urethane (meth)acrylate (A), another polyfunctional (meth)acrylate (B), an ultraviolet absorber (C), and a thermoplastic acrylic resin (D).

[0004] Patent Document 2 discloses an ultraviolet-curable urethane acrylate composition containing a urethane acrylate oligomer (E) having a (meth)acryloyl group at the molecular end, which is obtained by addition reaction of a (meth)acrylic compound (D) having a hydroxyl group with a urethane prepolymer (C) having an isocyanate group at the molecular end, which is obtained by reacting a polyol (A) having no aromatic skeleton with a polyisocyanate (B) having no aromatic skeleton.

[0005] Patent Document 3 discloses an active energy ray-curable composition containing a urethane (meth)acrylate which is a reaction product of a polyol (A-1) having a number average molecular weight of 500 or more, a polyol (A-2) having a number average molecular weight of less than 500, a non-yellowing organic polyisocyanate (B), and a hydroxyl group-containing (meth)acrylate (C). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-348499 [Patent Document 2] International Publication No. 2014 / 045782 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-133367 Summary of the Invention [Problem to be solved by the invention]

[0007] When a curable resin composition containing a urethane (meth)acrylate is cured, a cured layer with high hardness is formed as the crosslink density increases. Therefore, such a cured layer has high scratch resistance and is useful, for example, as a surface protective layer (hard coat layer). On the other hand, while the cured layer has high hardness, it has low elongation. Therefore, when a film having the cured layer is used in, for example, in-mold molding or insert molding, good molding processing may not be possible. Scratch resistance and elongation are in a trade-off relationship, and it is desirable to achieve both.

[0008] The present disclosure has been made in view of the above-mentioned circumstances, and has as its main object to provide a urethane (meth)acrylate that can provide a cured product layer that has both scratch resistance and elongation properties. [Means for solving the problem]

[0009] The present disclosure provides a urethane (meth)acrylate comprising: a structural unit a derived from a carbonate polyol compound (A) having a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and no cyclic skeleton; a structural unit b derived from an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups; a structural unit c derived from an alicyclic polyisocyanate compound (C); and a structural unit d derived from a hydroxyl group-containing (meth)acrylate compound (D); wherein the NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more; and the structural unit d is at a molecular chain terminal.

[0010] The present disclosure provides a urethane (meth)acrylate that is a reaction product of a urethane prepolymer having an isocyanate group at a molecular chain terminal, which is a reaction product of a carbonate polyol compound (A) that has a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and that does not have a cyclic skeleton, an alkyl alcohol compound (B) that has 10 or less carbon atoms and two or more hydroxyl groups, and an alicyclic polyisocyanate compound (C), and a hydroxyl group-containing (meth)acrylate compound (D), wherein the NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more.

[0011] The present disclosure provides a method for producing a urethane (meth)acrylate, comprising: a first step of reacting a carbonate polyol compound (A) having terminal hydroxyl groups, a number-average molecular weight of 500 or more and 1500 or less, and having no cyclic skeleton, an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups, and an alicyclic polyisocyanate compound (C) so that the NCO / OH ratio, which is the molar ratio of isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the alkyl alcohol compound (B), is 1.15 or more, to obtain a urethane prepolymer having isocyanate groups at its terminals; and a second step of reacting the urethane prepolymer with a hydroxyl group-containing (meth)acrylate compound (D) to obtain a urethane (meth)acrylate.

[0012] The present disclosure provides an active energy ray-curable resin composition containing the above-described urethane (meth)acrylate.

[0013] The present disclosure provides a transfer film having a release substrate, a hard coat layer, and an adhesive layer in this order in the thickness direction, wherein the hard coat layer is a cured product layer of the above-mentioned active energy ray-curable resin composition. [Effects of the Invention]

[0014] The present disclosure can provide a urethane (meth)acrylate capable of forming a cured product layer that has both scratch resistance and elongation properties. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view illustrating a transfer film according to the present disclosure. [Figure 2] 1 is a schematic cross-sectional view illustrating a transfer film according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments will be described with reference to the drawings. However, the present disclosure can be implemented in many different forms and should not be limited to the description of the embodiments exemplified below. Furthermore, in order to clarify the description, the drawings may schematically show the width, thickness, and shape of each part compared to the actual form, but this is merely an example and should not be interpreted as limiting.

[0017] In this specification, when describing a mode in which another component is placed on a certain component, the term "above" or "below" is used, unless otherwise specified, to include both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween. Also, in this specification, when describing a mode in which another component is placed on the surface of a certain component, the term "on the surface" or "on the surface side" is used, unless otherwise specified, to include both a case in which another component is placed directly above or below a certain component so as to be in contact with the component, and a case in which another component is placed above or below a certain component with another component interposed therebetween.

[0018] The urethane (meth)acrylate, the method for producing the urethane (meth)acrylate, the active energy ray-curable resin composition, and the transfer film according to the present disclosure will be described in detail below.

[0019] A. Urethane (meth)acrylate The urethane (meth)acrylates in the present disclosure are roughly divided into a first embodiment and a second embodiment.

[0020] A-1. First embodiment The urethane (meth)acrylate in this embodiment has a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and comprises a structural unit a derived from a carbonate polyol compound (A) that does not have a cyclic skeleton, a structural unit b derived from an alkyl alcohol compound (B) that has 10 or less carbon atoms and two or more hydroxyl groups, a structural unit c derived from an alicyclic polyisocyanate compound (C), and a structural unit d derived from a hydroxyl group-containing (meth)acrylate compound (D), wherein the NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more, and the structural unit d is present at a molecular chain terminal.

[0021] In this specification, the carbonate polyol compound (A) is sometimes simply referred to as component (A). Similarly, the alkyl alcohol compound (B), the alicyclic polyisocyanate compound (C), and the hydroxyl group-containing (meth)acrylate compound (D) are sometimes simply referred to as component (B), component (C), and component (D). In this specification, (meth)acrylate means acrylate or methacrylate, and (meth)acryloyl group means acryloyl group or methacryloyl group.

[0022] The urethane (meth)acrylate in this embodiment has a urethane polymer chain in which a structural unit a derived from the component (A) and a structural unit b derived from the component (B) are linked to a structural unit c derived from the component (C) by a urethane bond, and further, a structural unit d derived from the component (D) and having a (meth)acryloyl group is bonded to the end of the urethane polymer chain.

[0023] The urethane (meth)acrylate in this embodiment can also be said to be a reaction product of a urethane prepolymer having an isocyanate group at the molecular chain terminal, which is obtained by reacting the components (A), (B), and (C) so that the NCO / OH ratio is 1.15 or more, and the component (D).

[0024] According to this embodiment, component (A) that imparts flexibility, components (B) and (C) that impart hardness, and component (D) that imparts active energy ray curability are selected as compounds that derive the structural units of urethane (meth)acrylate, and by adjusting the amounts of components (A), (B), and (C) so that the NCO / OH ratio falls within a predetermined range, the balance between flexibility and hardness of the cured layer can be appropriately adjusted, and a cured layer that combines scratch resistance and elongation can be obtained.

[0025] Specifically, the inclusion of structural unit a derived from the carbonate polyol compound (A) with a number-average molecular weight equal to or greater than a predetermined value provides the cured layer with adequate flexibility, thereby improving extensibility. Furthermore, because the number-average molecular weight of the carbonate polyol compound (A) is equal to or less than a predetermined value, the cured layer does not become too soft, thereby preventing deterioration of scratch resistance. Chemical resistance is also improved. Furthermore, the absence of a cyclic skeleton in structural unit a prevents the cured layer from becoming too hard, providing self-healing properties (the ability to naturally repair scratches on the surface), thereby improving scratch resistance. Furthermore, the urethane bond connecting structural unit b derived from the alkyl alcohol compound (B) with a low carbon number and structural unit c derived from the alicyclic polyisocyanate compound (C) tends to aggregate, increasing the density of the cured layer and increasing its hardness, thereby improving scratch resistance. Furthermore, the urethane bond connecting structural unit b and structural unit c has high crystallinity and interaction, allowing it to bundle structural unit a, which ensures flexibility, thereby contributing to improved extensibility. Furthermore, the urethane (meth)acrylate contains the structural unit c derived from the alicyclic polyisocyanate compound (C), which enhances the hardness of the cured layer due to the interaction between the alicyclic structures, thereby improving scratch resistance. Furthermore, compared to a case where the urethane (meth)acrylate contains a structural unit derived from an aromatic polyisocyanate compound (a polyisocyanate compound having an aromatic ring), the weather resistance is also improved. Furthermore, the urethane (meth)acrylate contains the structural unit d derived from the hydroxyl group-containing (meth)acrylate compound (D) at the molecular chain terminal, which enhances curability with active energy rays.

[0026] Furthermore, in this embodiment, the NCO / OH ratio, which is the molar ratio of isocyanate groups in component (C) to the total hydroxyl groups in component (A) and component (B), is equal to or greater than a predetermined value, and therefore the constituent ratio of structural unit d derived from component (D) increases, thereby reducing the double bond equivalent of the urethane (meth)acrylate, thereby suppressing poor curing of the cured layer and improving scratch resistance and chemical resistance.

[0027] Hereinafter, each structural unit of the urethane (meth)acrylate in this embodiment will be described.

[0028] 1. Structural unit a derived from carbonate polyol compound (A) The urethane (meth)acrylate in this embodiment has a terminal hydroxyl group, a number average molecular weight of 500 to 1500, and a structural unit a derived from a carbonate polyol compound (A) that does not have a cyclic skeleton. The structural unit a has a structure in which the terminal hydroxyl group is removed from the carbonate polyol compound (A). The urethane (meth)acrylate in this embodiment may have a single type of structural unit a, or may have two or more types of structural units a.

[0029] The number-average molecular weight of the carbonate polyol compound (A) is 500 or more, preferably 800 or more. If the number-average molecular weight is too small, a cured layer having high elongation cannot be obtained. On the other hand, the number-average molecular weight of the carbonate polyol compound (A) is 1500 or less, preferably 1300 or less. If the number-average molecular weight is too large, the cured layer becomes too soft and the scratch resistance decreases.

[0030] Herein, the number average molecular weight of the carbonate polyol compound (A) is a calculated value obtained from the hydroxyl value, which is measured in accordance with JIS K1557-1.

[0031] The carbonate polyol compound (A) has at least one carbonate bond in the molecule, and also includes polycarbonate polyol compounds having two or more carbonate bonds. By having a carbonate bond in the molecule, a cured product layer having excellent scratch resistance, chemical resistance, and weather resistance can be obtained, for example, compared to when a polyester polyol compound having an ester structure as the main skeleton is used.

[0032] The carbonate polyol compound (A) does not have a cyclic skeleton. In this specification, the term "cyclic skeleton" refers to an alicyclic ring, an aromatic ring, a heterocyclic ring, or a skeleton containing one or more of these. The term "heterocyclic ring" refers to a cyclic structure having heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms as ring-constituting atoms. Because the carbonate polyol compound (A) does not have a cyclic skeleton, a cured material layer having excellent self-repairing properties and excellent scratch resistance can be obtained compared to when a carbonate polyol having a cyclic skeleton is used. If the carbonate polyol compound (A) has a cyclic skeleton, the cured material layer will be too hard and will have poor self-repairing properties, resulting in low scratch resistance.

[0033] The carbonate polyol compound (A) has two or more hydroxyl groups, at least one of which is a terminal hydroxyl group. The carbonate polyol compound (A) is preferably a carbonate diol having two hydroxyl groups in total, one at each end, and among these, an aliphatic carbonate diol represented by the following general formula (1) is preferred.

[0034] [ka] (In the formula, R is a linear or branched divalent hydrocarbon group, and multiple Rs contained in one molecule may be the same or different. n is a number that makes the number average molecular weight of the aliphatic carbonate diol represented by general formula (1) 500 or more and 1500 or less.)

[0035] In the above formula (1), R is a linear or branched divalent hydrocarbon group, and is preferably a linear or branched divalent saturated hydrocarbon group having 2 to 10 carbon atoms. Specific examples of R include ethylene, propylene, butylene, isobutylene, sec-butylene, tert-butylene, 2,2-dimethylpropylene, 2-methylbutylene, 2-methyl-2-butylene, 3-methylbutylene, 3-methyl-2-butylene, pentylene, 2-pentylene, 3-pentylene, 3-dimethyl-2-butylene, 3,3-dimethylbutylene, 3,3-dimethyl-2-butylene, 2-ethylbutylene, hexylene, 2-hexylene, 3-hexylene, 2-methylpentylene, 2-methyl-2-pentylene, 2-methyl-3-pentylene, 3-methylpentylene, 3-methyl-2-pentylene, and 3-methyl-3-pentylene. Examples of such groups include a 4-methylpentylene group, a 4-methyl-2-pentylene group, a 2,2-dimethyl-3-pentylene group, a 2,3-dimethyl-3-pentylene group, a 2,4-dimethyl-3-pentylene group, a 4,4-dimethyl-2-pentylene group, a 3-ethyl-3-pentylene group, a heptylene group, a 2-heptylene group, a 3-heptylene group, a 2-methyl-2-hexylene group, a 2-methyl-3-hexylene group, a 5-methylhexylene group, a 5-methyl-2-hexylene group, a 2-ethylhexylene group, a 6-methyl-2-heptylene group, a 4-methyl-3-heptylene group, an octylene group, a 2-octylene group, a 3-octylene group, a 2-propylpentylene group, a 2,4,4-trimethylpentylene group, a nonylene group, and a decanylene group. In the general formula (1), the plurality of Rs may be of a single type or of two or more types.

[0036] In the general formula (1), n ​​is not particularly limited as long as it is a number that makes the number average molecular weight of the aliphatic carbonate diol represented by the general formula (1) 500 or more and 1500 or less, and is, for example, a number of 3 or more and 9 or less.

[0037] The carbonate polyol compound (A) is synthesized, for example, by transesterification of a polyhydric alcohol with a carbonate ester. Examples of the polyhydric alcohol include polyhydric alcohols having either a linear alkyl structure or a branched alkyl structure. Examples of polyhydric alcohols having a linear alkyl structure include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanodiol, 1,10-dodecanediol, 1,11-undecanediol, and 1,12-dodecanediol. Examples of polyhydric alcohols having a branched alkyl structure include 2-methyl-1,8-octanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-dimethyl-1,3-propanediol. Polyhydric alcohols may be used alone or in combination. Examples of carbonate esters include ethylene carbonate, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, and dibutyl carbonate. Carbonate esters may be used alone or in combination.

[0038] 2. Alkyl alcohol compounds (B) The urethane (meth)acrylate in this embodiment has a structural unit b derived from an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups. The structural unit b has a structure in which a hydroxyl group is removed from the alkyl alcohol compound (B). The urethane (meth)acrylate in this embodiment may have a single type of structural unit b, or may have two or more types of structural units b.

[0039] The alkyl alcohol compound (B) is an alkyl alcohol compound having 10 or less carbon atoms. By using an alkyl alcohol compound with a short carbon chain, the hardness of the cured layer becomes high. The number of carbon atoms in the alkyl alcohol compound (B) is preferably 4 or more and 8 or less. The alkyl chain in the alkyl alcohol compound (B) may be linear, branched, or cyclic.

[0040] The alkyl alcohol compound (B) may have two or more hydroxyl groups per molecule. Among these, alkyl diols having two hydroxyl groups are preferred. Examples of alkyl diols include neopentyl glycol, 1,3-butanediol, 1,3-propanediol, cyclohexanedimethanol, propylene glycol, 2,3-butanediol, 1,4-butanediol, 2-ethylbutane-1,4-diol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-octanediol. These may be used alone or in combination of two or more.

[0041] 3. Alicyclic polyisocyanate compound (C) The urethane (meth)acrylate in this embodiment has a structural unit c derived from an alicyclic polyisocyanate compound (C). The structural unit c has a structure in which an isocyanate group is removed from the alicyclic polyisocyanate compound (C). The urethane (meth)acrylate in this embodiment may have a single type of structural unit c, or may have two or more types of structural units c.

[0042] The alicyclic polyisocyanate compound (C) is an isocyanate compound having two or more isocyanate groups in one molecule and having an alicyclic structure. In this embodiment, the use of the alicyclic polyisocyanate compound (C) improves scratch resistance. This is because the alicyclic structures interact with each other to form a pseudo-bonding state, thereby increasing hardness. On the other hand, when a linear isocyanate is used, scratch resistance deteriorates. From the viewpoint of weather resistance, the alicyclic polyisocyanate compound (C) is preferably a non-yellowing polyisocyanate that does not have an aromatic ring.

[0043] Examples of the alicyclic polyisocyanate compound (C) include bis(isocyanatomethyl)cyclohexane (HXDI) such as 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, 2,4-methylcyclohexane diisocyanate, 2,6-methylcyclohexane diisocyanate, cyclohexylene diisocyanate, and methylene diisocyanate. Examples of suitable diisocyanates include alicyclic diisocyanates such as ethylcyclohexylene diisocyanate, bis(2-isocyanatoethyl)-4-cyclohexylene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, dimer acid diisocyanate, bicycloheptane triisocyanate, and hydrogenated xylylene diisocyanate, as well as tri- or higher functional alicyclic polyisocyanates such as their adducts, isocyanurates, and biurets. These may be used alone or in combination of two or more.

[0044] The alicyclic polyisocyanate compound (C) is preferably a diisocyanate compound represented by the following general formula (2).

[0045] [ka] (In the formula, Xc is a divalent hydrocarbon group having an alicyclic structure and having 8 to 13 carbon atoms.)

[0046] Examples of the diisocyanate compound represented by the above formula (2) include 1,3-bis(isocyanatomethyl)cyclohexane (HXDI) and 4,4'-dicyclohexylmethane diisocyanate, with 1,3-bis(isocyanatomethyl)cyclohexane (HXDI) being preferred.

[0047] 4.NCO / OH ratio In this embodiment, the NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups of the hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more, preferably 1.30 or more. Having an NCO / OH ratio in the above range provides excellent scratch resistance and chemical resistance. Meanwhile, the NCO / OH ratio is preferably 1.50 or less, more preferably 1.40 or less.

[0048] 5. Hydroxyl group-containing (meth)acrylate compound (D) The urethane (meth)acrylate of this embodiment has a structural unit d at the molecular chain terminal. The structural unit d has a structure in which a hydroxyl group is removed from a hydroxyl group-containing (meth)acrylate compound (D). The urethane (meth)acrylate of this embodiment may have a single type of structural unit d, or may have two or more types of structural units d.

[0049] The hydroxyl group-containing (meth)acrylate compound (D) is a compound having one or more hydroxyl groups and one or more (meth)acryloyl groups. Examples of the hydroxyl group-containing (meth)acrylate compound (D) include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxyethyl-phthalic acid, trimethylolpropane di(meth)acrylate, glycerin di(meth)acrylate, dipentaerythritol penta(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane di(meth)acrylate, and ditrimethylolpropane tri(meth)acrylate.

[0050] The number of functional groups (number of (meth)acryloyl groups) in component (D) is preferably one. This is because a good balance between scratch resistance and elongation is achieved. Furthermore, the fewer the number of functional groups (number of (meth)acryloyl groups), the better the weather resistance. On the other hand, the number of functional groups (number of (meth)acryloyl groups) in component (D) may be two or more. The number of hydroxyl groups in component (D) is not particularly limited, but is preferably one. Component (D) is preferably a compound having one hydroxyl group and one (meth)acryloyl group. An example of such a component (D) is hydroxyethyl (meth)acrylate.

[0051] 6. Urethane (meth)acrylate The weight average molecular weight of the urethane (meth)acrylate in this embodiment is, for example, 5,000 or more and 10,000 or less, and may be 6,000 or more and 9,000 or less. The weight average molecular weight of the urethane (meth)acrylate can be measured by the method described in the Examples. From the viewpoint of crosslinking and curing, the urethane (meth)acrylate in this embodiment preferably has two or more (meth)acryloyl groups in the molecule, and more preferably has two (meth)acryloyl groups.

[0052] The urethane (meth)acrylate in this embodiment has, for example, a structure represented by the following general formula (3): The urethane (meth)acrylate represented by the following general formula (3) is an example of a urethane (meth)acrylate structure when a carbonate diol is used as the component (A), an alkyl diol is used as the component (B), a diisocyanate compound is used as the component (C), and a compound having one hydroxyl group and one (meth)acryloyl group in the molecule is used as the component (D).

[0053] [ka] (In the formula, Ra represents the above-mentioned structural unit a, Rb represents the above-mentioned structural unit b, Rc represents the above-mentioned structural unit c, and Rd represents the above-mentioned structural unit d. p and q represent the average number of repetitions of each repeating unit, p is a number from 1 to 2, and q is a number from 1 to 4. The arrangement order of each repeating unit is not particularly limited, and may be random or block.)

[0054] The urethane (meth)acrylate in this embodiment preferably has a structure in which the combination of p and q is (p, q) = (1, 1), (1, 2), or (2, 4) among the structures represented by the general formula (3). Note that (p, q) = (1, 1) means that p = 1 and q = 1.

[0055] A-2. Second embodiment The urethane (meth)acrylate in this embodiment is a reaction product of a urethane prepolymer having an isocyanate group at a molecular chain terminal, which is a reaction product of a carbonate polyol compound (A) having a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and not having a cyclic skeleton, an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups, and an alicyclic polyisocyanate compound (C), and a hydroxyl group-containing (meth)acrylate compound (D), and the NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more.

[0056] The urethane (meth)acrylate in this embodiment has a urethane polymer chain in which a structural unit a derived from the component (A) and a structural unit b derived from the component (B) are linked to a structural unit c derived from the component (C) by a urethane bond, and further, a structural unit d derived from the component (D) and having a (meth)acryloyl group is bonded to the end of the urethane polymer chain.

[0057] According to this embodiment, by selecting the (A) component that imparts flexibility, the (B) and (C) components that impart hardness, and the (D) component that imparts active energy ray curability as compounds that derive the urethane (meth)acrylate structural unit, and adjusting the amounts of the (A), (B), and (C) components so that the NCO / OH ratio falls within a predetermined range, the balance between flexibility and hardness of the cured product layer can be appropriately adjusted, and a cured product layer that combines scratch resistance and elongation can be obtained. Specifically, this is as described in detail in the first embodiment.

[0058] The urethane (meth)acrylate in this embodiment is a reaction product of a urethane prepolymer obtained by reacting components (A) to (C) at a predetermined NCO / OH ratio, and component (D). Details of each component and the NCO / OH ratio are the same as those described in "A-1. First Embodiment" above. Other characteristics of the urethane (meth)acrylate are the same as those described in "A-1. First Embodiment" above.

[0059] B. Method for producing urethane (meth)acrylate The present disclosure provides a method for producing a urethane (meth)acrylate, comprising: a first step of reacting a carbonate polyol compound (A) having terminal hydroxyl groups, a number-average molecular weight of 500 or more and 1500 or less, and having no cyclic skeleton, an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups, and an alicyclic polyisocyanate compound (C) so that the NCO / OH ratio, which is the molar ratio of isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the alkyl alcohol compound (B), is 1.15 or more, to obtain a urethane prepolymer having isocyanate groups at its terminals; and a second step of reacting the urethane prepolymer with a hydroxyl group-containing (meth)acrylate compound (D) to obtain a urethane (meth)acrylate.

[0060] According to the method for producing a urethane (meth)acrylate of the present disclosure, a urethane (meth)acrylate capable of forming a cured product layer that has both scratch resistance and elongation can be produced by carrying out steps 1 and 2. Each step will be described in detail below.

[0061] 1.First step The first step is to obtain a urethane prepolymer having an isocyanate group at its terminal by reacting components (A), (B), and (C) so that the NCO / OH ratio is 1.15 or greater. The components (A), (B), and (C) and the NCO / OH ratio are the same as those described above.

[0062] When reacting the components, the molar ratio of component (A) to component (B) (number of moles of component (A) / number of moles of component (B)) is, for example, preferably 10 / 90 or more, more preferably 30 / 70 or more, and preferably 90 / 10 or less, more preferably 50 / 50 or less.

[0063] The specific method for reacting components (A), (B), and (C) to obtain a urethane prepolymer is not particularly limited, but for example, components (A), (B), and optionally a solvent may be mixed, to which component (C) is added for reaction. The reaction is preferably carried out at a temperature of 60°C to 110°C, and preferably in the presence of a catalyst.

[0064] Examples of catalysts include amine compounds such as triethylamine, piperazine, and triethanolamine, and organometallic compounds. Examples of organometallic compounds include organotin compounds such as dibutyltin dilaurate, tin octoate, tin laurate, and dioctyltin dilaurate, organozinc compounds such as zinc 2-ethylhexanoate, organozirconium compounds such as zirconium tetraacetylacetonate, and organobismuth compounds such as bismuth trioctate. In this step, a urethane prepolymer having an isocyanate group at its terminal is obtained.

[0065] The end point of the urethane reaction in the first step can be confirmed by determining the content of isocyanate groups by the method described in JIS K 7301.

[0066] 2.Second process The second step is a step of reacting the urethane prepolymer obtained in the first step with component (D) to obtain a urethane (meth)acrylate. For example, component (D) is added to the reaction vessel in which the urethane prepolymer was produced and reacted. The reaction is preferably carried out under conditions of 60°C or higher and 110°C or lower, and additives such as a catalyst, polymerization inhibitor, and antioxidant may be further added.

[0067] Examples of the catalyst include the same types as those exemplified in the first step. It is preferable that the catalyst used in the first step and the catalyst used in the second step are the same type. Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, p-methoxyphenol, and p-benzoquinone. Examples of antioxidants include dibutylhydroxytoluene, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], and octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate. phenolic antioxidants such as octylthiomethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, N,N-hexamethylenebis(3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 2,4-bis[(octylthio)methyl]-O-cresol, and isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; amine-based antioxidants such as octylated diphenylamine; phosphorus-based antioxidants such as triphenyl phosphite and bis(tridecyl)pentaerythritol diphosphite; and sulfur-based antioxidants such as didodecyl 3,3′-thiodipropionate.

[0068] The end point of the urethane reaction in the second step is 2270 cm, which indicates an isocyanate group. -1 This can be confirmed by the disappearance of the infrared absorption spectrum.

[0069] The structure of the urethane (meth)acrylate produced by the method for producing a urethane (meth)acrylate according to the present disclosure is the same as that described above in "A. Urethane (meth)acrylate."

[0070] C. Active energy ray-curable resin composition The present disclosure provides an active energy ray-curable resin composition containing the above-mentioned urethane (meth)acrylate. Because the active energy ray-curable resin composition of the present disclosure contains the above-mentioned urethane (meth)acrylate, it is possible to form a cured product layer that combines scratch resistance and elongation by irradiation with active energy rays. Therefore, the active energy ray-curable resin composition of the present disclosure can be suitably used as a material for forming a hard coat layer in a film for molding (a sheet for molding). Examples of molding processes include in-mold molding and insert molding. In this specification, the active energy ray-curable resin composition is also simply referred to as a "curable resin composition."

[0071] 1.Polymerizable compound The active energy ray-curable resin composition contains at least the above-mentioned urethane (meth)acrylate as a polymerizable compound. The active energy ray-curable resin composition may contain a polymerizable compound other than the above-mentioned urethane (meth)acrylate. The content of the above-mentioned urethane (meth)acrylate relative to a total of 100 parts by mass of the polymerizable compounds contained in the active energy ray-curable resin composition is, for example, 50 parts by mass or more, or may be 80 parts by mass or more, or may be 90 parts by mass or more. On the other hand, it is, for example, 100 parts by mass or less.

[0072] The other polymerizable compound is not particularly limited as long as it is a polymerizable compound having an ethylenically unsaturated bond-containing group, and examples thereof include compounds such as polymers (high polymers), oligomers (low polymers), and monomers (monomers), and known compounds can be used as appropriate. The polymerizable compound having an ethylenically unsaturated bond-containing group can be used alone or in combination of two or more.

[0073] 2. Additives The active energy ray-curable resin composition according to the present disclosure may contain other components such as an ultraviolet absorber, fine particles, and a polymerization initiator as additives.

[0074] (1) UV absorbers The curable resin composition of the present disclosure may contain an ultraviolet absorber in order to improve weather resistance. By containing an ultraviolet absorber, the curable resin composition of the present disclosure is likely to achieve high weather resistance. The ultraviolet absorber may be used alone or in combination of two or more.

[0075] Examples of the ultraviolet absorber include benzotriazole-based compounds, benzophenone-based compounds, triazine-based compounds, cyanoacrylate-based compounds, benzoxazinone-based compounds, benzoxazole-based compounds, and merocyanine-based compounds, and benzotriazole-based compounds, benzophenone-based compounds, and triazine-based compounds are more preferred.

[0076] (2) Fine particles The curable resin composition of the present disclosure may contain fine particles from the viewpoint of increasing the hardness or adjusting the refractive index when formed into a cured product layer. The fine particles may be inorganic or organic, but inorganic fine particles are preferred from the viewpoint of imparting hardness. Examples of inorganic fine particles include metal oxide fine particles such as silica (SiO), aluminum oxide, zirconia, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and cerium oxide, and metal fluoride fine particles such as magnesium fluoride and sodium fluoride.

[0077] (3) Polymerization initiator When the curable resin composition of the present disclosure is UV-curable and uses ultraviolet light for curing, it may contain a photopolymerization initiator, a polymerization accelerator, a photoinitiation aid, etc. to rapidly cure the composition. Examples of the photopolymerization initiator include acetophenone-based compounds, benzoin ether-based compounds, benzophenone-based compounds, and thioxanthone-based compounds. The photopolymerization initiator may be used alone or in combination of two or more.

[0078] The content ratio of the photopolymerization initiator is not particularly limited, but may be, for example, 0.1 to 30 parts by mass, or 1 to 5 parts by mass, relative to 100 parts by mass of the total amount of polymerizable compounds contained in the curable resin composition. Examples of polymerization accelerators and photoinitiation aids include triethanolamine, methyldiethanolamine, and triisopropanolamine. The content ratio of the polymerization accelerator and photoinitiation aid is not particularly limited, but may be, for example, 0.01 to 10 parts by mass, or 0.5 to 3 parts by mass, relative to 100 parts by mass of the photopolymerization initiator.

[0079] In addition, when the composition is made electron beam curable using an electron beam for curing, it is not necessary to add a photopolymerization initiator, a polymerization accelerator, a photoinitiation aid, etc. In this case, the content of the polymerizable compound in the solid content can be increased, which is preferable because it is easy to improve scratch resistance and elongation.

[0080] (4) Other additives The curable resin composition of the present disclosure may further contain various additives, such as a light stabilizer, an antioxidant, a plasticizer, a flame retardant, a surfactant, a leveling agent, a thermal polymerization inhibitor, an antistatic agent, an antifogging agent, an antibacterial agent, a filler, a pigment, a dye, and a colorant, as needed.

[0081] (5) Solvent The curable resin composition may contain a solvent to adjust the viscosity of the composition or to improve the smoothness, uniformity, and adhesion of the cured layer to the substrate. Known solvents can be used, including, for example, alcohols such as ethanol, propanol, isopropanol, and butanol; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and ethers such as 2-methoxyethanol, 2-ethoxyethanol, 2-ethoxypropanol, 2-(2-ethoxyethoxy)ethanol, 1,4-dioxane, and tetrahydrofuran. The solvents may be used alone or in combination of two or more.

[0082] In the curable resin composition, the content of the solvent may be adjusted appropriately depending on the purpose and is not particularly limited, but is preferably 30 parts by mass or more and 90 parts by mass or less, and more preferably 40 parts by mass or more and 70 parts by mass or less, per 100 parts by mass of the curable resin composition.

[0083] The curable resin composition of the present disclosure can be obtained by blending urethane (meth)acrylate, various additives, and a solvent in predetermined ratios and mixing them uniformly by a conventional method.

[0084] 3.Cured material layer The curable resin composition of the present disclosure is cured by irradiation with active energy rays, such as ultraviolet rays emitted from light sources such as xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, and tungsten lamps, as well as electron beams, α-rays, β-rays, and γ-rays typically extracted from particle accelerators of 20 to 2000 kV.

[0085] The cured product layer of the curable resin composition of the present disclosure has excellent scratch resistance. When the cured product layer of the curable resin composition of the present disclosure is subjected to a Taber abrasion test in accordance with JIS K5600-5-9 (1999) using an abrasion wheel CS-10F, a load of 500 g, and a rotation speed of 500 rpm, and the difference in haze value ΔH% before and after the test is measured, the ΔH% is preferably 10% or less. The haze value is measured in accordance with JIS K7136.

[0086] The cured product layer of the curable resin composition according to the present disclosure has excellent elongation. In a thermal tensile test at 180°C, the cured product layer of the curable resin composition according to the present disclosure preferably has an elongation, which is the ratio of the elongation length at which cracks occur to the length before the test, of 70% or more, and more preferably 80% or more. Note that 180°C is a temperature that simulates the temperature of molten resin in injection molding. The elongation of the cured product layer is a value measured by the method described in the examples.

[0087] 4.Applications The cured product layer of the curable resin composition is preferably used in applications requiring extensibility under high-temperature conditions during production or use, and further has weather resistance, so is also preferably used in applications where the curable resin composition is directly exposed to ultraviolet rays, sunlight, or moisture. The curable resin composition of the present disclosure is preferably used, for example, as a building material and an interior / exterior component of transportation equipment such as automobiles, trains, and airplanes, particularly as a protective layer material for exterior components.

[0088] D. Transfer film The present disclosure provides a transfer film having a release substrate, a hard coat layer, and an adhesive layer in this order in the thickness direction, wherein the hard coat layer is a cured product layer of the above-mentioned active energy ray-curable resin composition.

[0089] 1 and 2 are schematic cross-sectional views illustrating examples of transfer films according to the present disclosure. As shown in Fig. 1, a transfer film 10 has a release substrate 1, a hard coat layer 2, and an adhesive layer 3, in this order in the thickness direction. The hard coat layer 2 is a cured product layer of the above-described active energy ray-curable resin composition. As shown in Fig. 2, the transfer film 10 may have a primer layer 4 between the hard coat layer 2 and the adhesive layer 3.

[0090] The transfer film according to the present disclosure has high scratch resistance and high elongation because the hard coat layer is a cured product layer of the active energy ray-curable resin composition described above, and therefore can be suitably used as an in-mold transfer film.

[0091] 1. Hard coat layer The hard coat layer is a cured product layer of the active energy ray-curable resin composition described above. The hard coat layer can be produced by coating the curable resin composition described above to a desired thickness on a release substrate, drying the coating to remove the solvent as necessary, and then irradiating the coating with active energy rays to cure the coating.

[0092] The method for applying the curable resin composition to the release substrate is not particularly limited, and any known method can be used as appropriate. Examples of the application method include dipping, flow coating, spraying, spin coating, gravure coating, microgravure coating, die coating, slit reverse coating, roll coating, blade coating, air knife coating, offset coating, and bar coating. In addition, the composition can also be applied in an imagewise manner by printing methods such as gravure printing, gravure offset printing, and screen printing.

[0093] The amount of coating is not particularly limited, but it is preferable to coat the cured product layer so that the film thickness is 0.1 μm or more and 200 μm or less, preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

[0094] When the curable resin composition contains a solvent, drying may be performed after coating to evaporate the solvent. Known methods such as hot air heating, infrared heating, and far-infrared heating can be appropriately used for drying. The preferred drying conditions vary depending on the boiling point of the solvent, the material of the release substrate, the coating amount, and the like, but for example, the heating temperature can be 30°C or higher and 120°C or lower, and the heating time can be 1 minute or higher and 30 minutes or lower. Since the active energy ray was described in detail above in "C. Active energy ray-curable resin composition," a detailed description thereof will be omitted here.

[0095] 2.Release substrate The release substrate of the transfer film is not particularly limited as long as it can support the hard coat layer so as to be used for transferring the hard coat layer.

[0096] The release substrate has, for example, a resin film. Examples of resin films include polyethylene (PE) resin, polypropylene (PP) resin, polybutadiene resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate resin, polyethylene naphthalate (PEN) resin, triacetyl cellulose (TAC) resin, polymethyl methacrylate (PMMA) resin, polycarbonate (PC) resin, cycloolefin polymer, ethylene vinyl acetate copolymer (EVA) resin, polyvinyl chloride (PVA) resin, ABS resin, and AS resin. Among these, polyethylene terephthalate (PET) resin and other films are preferably used in terms of dimensional stability, releasability, and the like.

[0097] The resin film may be subjected to a surface treatment to improve releasability. Such surface treatment is generally carried out by applying a release agent. Examples of the release agent include fluororesin, silicone resin, and long-chain alkyl resin compounds.

[0098] The release substrate may have a resin film and a release layer disposed on the surface of the resin film facing the transfer layer. The release layer is not particularly limited as long as it is made of a material having releasability, but examples thereof include silicone resin, organic resin-modified silicone resin, fluororesin, aminoalkyd resin, melamine resin, acrylic resin, and polyester resin. The thickness of the release layer is not particularly limited, but examples thereof include 0.1 μm to 10 μm, and preferably 0.5 μm to 2 μm.

[0099] 3.Adhesive layer The adhesive layer can be appropriately selected and used as long as it has the function of adhering the substrate to the hard coat layer or other layers. The adhesive layer may be present between other layers.

[0100] The adhesive layer is preferably a heat seal layer. The heat seal layer contains a thermoplastic resin that can be welded by heat. The thermoplastic resin is not particularly limited, and examples thereof include acrylic resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, polyester resin, chlorinated polypropylene, chlorinated rubber, urethane resin, epoxy resin, and styrene resin. The above resins are used alone or in combination of two or more. The thickness of the heat seal layer is not particularly limited, and can be, for example, 1 μm to 7 μm, and preferably 1 μm to 6 μm.

[0101] 4. Other layers 2, the transfer film according to the present disclosure may have a primer layer 4 between a hard coat layer 2 and an adhesive layer 3. Although not specifically shown, the transfer film may further include another layer such as a decorative layer.

[0102] A primer layer may be further provided when the adhesion between the hard coat layer, which is a cured product layer of the curable resin composition, and another layer such as the heat seal layer is insufficient. Examples of materials that can be used for the primer layer include, but are not limited to, acrylic resins, urethane resins, vinyl chloride / vinyl acetate copolymer resins, polyester resins, and chlorinated polyolefin resins. The thickness of the primer layer is not particularly limited, but is, for example, 0.1 μm or more and 10 μm or less.

[0103] The decorative layer may be disposed between the hard coat layer and the adhesive layer.

[0104] 5.Applications The transfer film of the present disclosure can be suitably used for applications requiring use under high temperature conditions, such as in-mold transfer, because the hard coat layer, which is a cured layer of the above-mentioned curable resin composition, has excellent elongation under high temperature conditions and excellent scratch resistance.

[0105] In the case of in-mold transfer, the transfer film of the present disclosure is inserted into an injection mold so that the release substrate is in contact with the mold, and then a heated and molten resin is injected to fill the cavity, followed by cooling and opening the mold, thereby allowing molding and transfer to be performed simultaneously. By peeling off the release substrate after molding, a cured layer of the curable resin composition as a hard coat layer and, in some cases, other layers such as a decorative layer are transferred to the resin molded product.

[0106] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits similar effects is included within the technical scope of the present disclosure. [Example]

[0107] The components used in Examples 1 to 6 and Comparative Examples 1 to 6 below are as follows. Component (A): Polymer polyol compound A1: Kuraray Polyol C-1090 (manufactured by Kuraray Co., Ltd., a reaction product of acyclic carbonate (3-methyl-1,5-pentanediol / 1,6-hexanediol = 90 / 10 (mol%)) and carbonate ester, number average molecular weight 1,000) A2: Benebiol NL1030DB (manufactured by Mitsubishi Chemical Corporation, a reaction product of acyclic carbonate (1,10-decanediol / 1,4-butanediol = 30 / 70 (mol%) and carbonate ester), number average molecular weight 1,000) A3: Kuraray Polyol P-2010 (Kuraray Co., Ltd., acyclic skeletal ester (reaction product of 3-methyl-1,5-pentanediol and adipic acid), number average molecular weight 2,000) A4: Kuraray Polyol C-2090 (Kuraray Co., Ltd., acyclic carbonate (3-methyl-1,5-pentanediol / 1,6-hexanediol = 90 / 10 (mol%) reaction product with carbonate ester), number average molecular weight 2,000) A5: Benebiol HS0850H (manufactured by Mitsubishi Chemical Corporation, a reaction product of a cyclic carbonate (isosorbite / 1,6-hexanediol = 50 / 50 (mol%) and a carbonate ester), number average molecular weight 800)

[0108] (B) Component: Alkyl alcohol compound B1: Neopentyl glycol B2: 1,3-butylene glycol B3: Cyclohexanedimethanol

[0109] Component (C): Polyisocyanate C1: 1,3-bis(isocyanatomethyl)cyclohexane (HXDI) C2: Xylylene diisocyanate (XDI)

[0110] Component (D): OH group-containing acrylate D1: 2-hydroxyethyl acrylate

[0111] (additives) Antioxidants AO1: Dibutylhydroxytoluene Polymerization inhibitor X1: p-Methoxyphenol ·catalyst Y1: Dioctyltin neodecanoate

[0112] Example 1 The above-mentioned A1 was used as the component (A), the above-mentioned B1 as the component (B), and the above-mentioned C1 as the component (C) in methyl ethyl ketone as the solvent, and they were mixed in the amounts (parts by mass) shown in Table 1, and the temperature was raised to 60°C. Next, the above-mentioned Y1 was used as the catalyst, and the amounts shown in Table 1 were mixed, and the temperature was raised to 75°C. The reaction was carried out sufficiently to synthesize a urethane prepolymer having structural units a, b, and c and having isocyanate groups at its terminals (Step 1). Note that the amounts were adjusted so that the NCO / OH ratio, which is the molar ratio of isocyanate groups in component (C) to the total hydroxyl groups in component (A) and component (B), would be the value shown in Table 1. Next, the above D1 as component (D), the above AO1 as antioxidant, the above X1 as polymerization inhibitor, and the above Y1 as catalyst were added dropwise in the amounts shown in Table 1 (for the catalyst, only an amount that would result in the cumulative amount shown in Table 1), and reacted with the urethane prepolymer to obtain a methyl ethyl ketone solution of urethane (meth)acrylate (Step 2). The weight-average molecular weight of the resulting urethane (meth)acrylate is shown in Table 3.

[0113] The weight-average molecular weight (Mw) was determined by gel permeation chromatography (GPC) using a Tosoh GPC HLC-8320 with two Shodex LF-404 columns connected in series, a refractive index (RI) detector, and Agilent Technologies Easyal Type PS-2 polystyrene (molecular weight range: 580-364,000) as the standard polystyrene. The resulting urethane acrylate was dissolved in THF to a sample concentration of 0.2 wt%. The mobile phase was THF, the flow rate was 0.30 mL / min, the column temperature was 40 °C, and the sample injection volume was 10 μL.

[0114] (Preparation of laminate) A curable resin composition containing the urethane (meth)acrylate synthesized above and a solvent (methyl ethyl ketone (MEK) in the table) was prepared. The curable resin composition was applied to a 50 μm-thick PET film (polyester film Cosmoshine A4160, manufactured by Toyobo Co., Ltd.) to a dry thickness of 4 μm, and then dried at 90°C for 60 seconds to form a coating. The coating was then irradiated with an electron beam at 8 Mrad and 165 kV to obtain a laminate with a cured layer of the curable resin composition on its surface.

[0115] (Examples 2 to 6, Comparative Examples 1 to 6) Curable resin compositions containing urethane (meth)acrylate were prepared and laminates were obtained in the same manner as in Example 1, except that the types and amounts of each component were changed as shown in Tables 1 and 2.

[0116] [Table 1]

[0117] [Table 2]

[0118] [Elongation under high temperature conditions] The laminates obtained in the examples and comparative examples were cut into pieces measuring 2.5 cm x 10 cm. A tensile test was carried out on these samples using a tensile tester (AUTOGRAPH AG-Xplus manufactured by Shimadzu Corporation) at 180°C, with a chuck distance of 5 cm and a pulling speed of 100 mm / min. The length of elongation when cracks appeared in the cured layer was measured, and the elongation was calculated and evaluated as follows: Elongation = (length of elongation when cracks appear in the cured layer) / (distance between chucks 5 cm) x 100 (%) <Evaluation criteria> A: 70% or more B: Less than 70%

[0119] [Scratch resistance evaluation] The laminates obtained in the examples and comparative examples were cut into pieces measuring 10 cm x 10 cm, and the samples were subjected to a Taber abrasion test in accordance with JIS K 5600 using an abrasion wheel CS-10F, a load of 500 g, and a rotation speed of 500 rpm. The difference in haze value ΔH (%) before and after the test was measured, and the samples were evaluated according to the following evaluation criteria. <Evaluation criteria> A: 10% or less B: More than 10%

[0120] [Chemical resistance evaluation] Resistance to the chemicals shown in Tables 3 and 4 was evaluated in accordance with "JIS K 5600-6-1 9. Method 3 (Drip Method) Procedure A (Horizontal Method)." The laminates obtained in the Examples and Comparative Examples were cut into pieces measuring 5 cm x 5 cm, and the chemicals shown in Tables 3 and 4 were dropped onto the cured layer of the sample using a pipette. The test liquid was then covered with a petri dish, and the sample was left at room temperature (23±2°C) for 1 hour and then for 24 hours, after which changes were observed. <Evaluation criteria> A: The surface condition of the cured layer is visually inspected and there are no changes in appearance such as wrinkles, swelling, peeling, or discoloration. B: The surface condition of the cured layer is visually inspected and there are changes in appearance such as wrinkles, swelling, peeling, and discoloration.

[0121] [Weather resistance] The laminates obtained in the examples and comparative examples were subjected to an irradiation test in which a xenon lamp was irradiated from the cured product layer side for 1500 hours under the following conditions (1) and (2) repeatedly using a 7.5 kW Super Xenon Weather Meter SX75 manufactured by Suga Test Instruments Co., Ltd. as a weather resistance tester, and the laminates were evaluated according to the following evaluation criteria. <Condition (1): Irradiation> ·Irradiance: 180W / m2 Black Panel Temperature (BPT): 63°C ·Humidity: 50% ·Water spray: none Duration: 102 minutes <Condition (2): Irradiation + Rainfall> ·Irradiance: 180W / m2 Black Panel Temperature (BPT): 28°C ·Humidity: 95% ·Water spray: Yes Duration: 18 minutes <Evaluation criteria> A: After 1500 hours of weather resistance testing, the surface condition of the cured layer was visually inspected and no cracks were found on the surface of the 25mm x 25mm sample. B: After 1500 hours of weather resistance testing, the surface condition of the cured layer was visually inspected and cracks were found on the surface of a 25 mm x 25 mm sample.

[0122] [Table 3]

[0123] [Table 4]

[0124] As shown in Tables 3 and 4, it was confirmed that the curable resin compositions containing the urethane (meth)acrylates of Examples 1 to 6 could provide cured layers that had excellent elongation under high temperature conditions and excellent scratch resistance, chemical resistance, and weather resistance.

[0125] On the other hand, Comparative Example 1, in which a polyester polyol was used instead of a polycarbonate polyol as the urethane (meth)acrylate material, was confirmed to have low abrasion resistance, chemical resistance, and weather resistance. Furthermore, Comparative Example 2, in which a polycarbonate polyol with a high number-average molecular weight was used, experienced poor curing, making the abrasion resistance test unmeasurable. Also, poor weather resistance and chemical resistance were confirmed. Comparative Example 3, in which a polycarbonate polyol having a cyclic skeleton was used, was confirmed to have low abrasion resistance because the cured product layer was too hard and had poor self-repairing properties. Comparative Example 4, in which component (B) was not used, was confirmed to have low elongation and abrasion resistance. Comparative Example 5, in which the NCO / OH ratio in the first step was low, was confirmed to have low abrasion resistance and chemical resistance, and Comparative Example 6, in which an aromatic polyisocyanate was used as component (C), was confirmed to have low abrasion resistance and weather resistance.

[0126] Thus, the present disclosure provides, for example, the following inventions.

[0127] [1] a structural unit a derived from a carbonate polyol compound (A) that has a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and does not have a cyclic skeleton; a structural unit b derived from an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups; A structural unit c derived from an alicyclic polyisocyanate compound (C), and a structural unit d derived from a hydroxyl group-containing (meth)acrylate compound (D), an NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more; A urethane (meth)acrylate having the structural unit d at a molecular chain terminal.

[0128] [2] a carbonate polyol compound (A) having a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and not having a cyclic skeleton; an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups, and a urethane prepolymer having an isocyanate group at the molecular chain terminal, which is a reaction product of an alicyclic polyisocyanate compound (C); and a hydroxyl group-containing (meth)acrylate compound (D), A urethane (meth)acrylate in which an NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more.

[0129] [3] The urethane (meth)acrylate according to [1] or [2], wherein the NCO / OH ratio is 1.50 or less.

[0130] [4] The urethane (meth)acrylate according to any one of [1] to [3], wherein the alkyl alcohol compound (B) has 4 or more and 8 or less carbon atoms.

[0131] [5] The urethane (meth)acrylate according to any one of [1] to [4], wherein the carbonate polyol compound (A) has a number average molecular weight of 800 or more and 1,500 or less.

[0132] [6] The urethane (meth)acrylate according to any one of [1] to [5], wherein the carbonate polyol compound (A) is a carbonate diol having two terminal hydroxyl groups.

[0133] [7] The urethane (meth)acrylate according to any one of [1] to [6], wherein the alicyclic polyisocyanate compound (C) is non-yellowing.

[0134] [8] a carbonate polyol compound (A) having a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and not having a cyclic skeleton; an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups, and An alicyclic polyisocyanate compound (C), a first step of reacting the alicyclic polyisocyanate compound (C) with the hydroxyl groups in the carbonate polyol compound (A) and the alkyl alcohol compound (B) so that the NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the alkyl alcohol compound (B), is 1.15 or more, thereby obtaining a urethane prepolymer having isocyanate groups at its terminals; and The method for producing a urethane (meth)acrylate comprises a second step of reacting the urethane prepolymer with a hydroxyl group-containing (meth)acrylate compound (D) to obtain a urethane (meth)acrylate.

[0135] [9] An active energy ray-curable resin composition comprising the urethane (meth)acrylate according to any one of [1] to [7].

[0136]

[10] The active energy ray-curable resin composition according to [9], which is used for a hard coat layer of a film for molding processing.

[0137]

[11] A transfer film having a release substrate, a hard coat layer, and an adhesive layer in this order in a thickness direction, The transfer film, wherein the hard coat layer is a layer of a cured product of the active energy ray-curable resin composition according to [9] or

[10] .

[0138]

[12] The transfer film according to

[11] , wherein the adhesive layer is a heat seal layer. [Explanation of symbols]

[0139] 1...Release substrate 2...Hard coat layer 3...adhesive layer 4...Primer layer 10...Transfer film

Claims

1. a structural unit a derived from a carbonate polyol compound (A) which has a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and which does not have a cyclic skeleton; a structural unit b derived from an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups; A structural unit c derived from an alicyclic polyisocyanate compound (C), and a structural unit d derived from a hydroxyl group-containing (meth)acrylate compound (D), an NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more; A urethane (meth)acrylate having the structural unit d at the molecular chain terminal.

2. a carbonate polyol compound (A) having a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and not having a cyclic skeleton; an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups; and a urethane prepolymer having an isocyanate group at the molecular chain terminal, which is a reaction product of an alicyclic polyisocyanate compound (C); and a hydroxyl group-containing (meth)acrylate compound (D), a molar NCO / OH ratio, which is the molar ratio of isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the alkyl alcohol compound (B), of 1.15 or more;

3. 3. The urethane (meth)acrylate according to claim 1, wherein the NCO / OH ratio is 1.50 or less.

4. The urethane (meth)acrylate according to claim 1 or 2, wherein the alkyl alcohol compound (B) has 4 or more and 8 or less carbon atoms.

5. The urethane (meth)acrylate according to claim 1 or 2, wherein the carbonate polyol compound (A) has a number average molecular weight of 800 or more and 1,500 or less.

6. 3. The urethane (meth)acrylate according to claim 1 or 2, wherein the carbonate polyol compound (A) is a carbonate diol having two terminal hydroxyl groups.

7. The urethane (meth)acrylate according to claim 1 or 2, wherein the alicyclic polyisocyanate compound (C) is a non-yellowing type.

8. a carbonate polyol compound (A) having a terminal hydroxyl group, a number average molecular weight of 500 or more and 1500 or less, and not having a cyclic skeleton; an alkyl alcohol compound (B) having 10 or less carbon atoms and two or more hydroxyl groups; and An alicyclic polyisocyanate compound (C), a first step of reacting the alicyclic polyisocyanate compound (C) with the alicyclic polyisocyanate compound (C) so that an NCO / OH ratio, which is the molar ratio of the isocyanate groups in the alicyclic polyisocyanate compound (C) to the total hydroxyl groups in the carbonate polyol compound (A) and the hydroxyl groups in the alkyl alcohol compound (B), is 1.15 or more, thereby obtaining a urethane prepolymer having isocyanate groups at its terminals; and a second step of reacting the urethane prepolymer with a hydroxyl group-containing (meth)acrylate compound (D) to obtain a urethane (meth)acrylate.

9. An active energy ray-curable resin composition comprising the urethane (meth)acrylate according to claim 1 or 2.

10. The active energy ray-curable resin composition according to claim 9, which is used for a hard coat layer of a film for molding processing.

11. A transfer film having a release substrate, a hard coat layer, and an adhesive layer in this order in a thickness direction, A transfer film, wherein the hard coat layer is a layer of a cured product of the active energy ray-curable resin composition according to claim 9.

12. The transfer film according to claim 11 , wherein the adhesive layer is a heat seal layer.

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